I'm having similar problems. My Goodreads widget was showing up blank, even though everything in the widget is correct. I even changed themes, and my widget worked for maybe an hour, and now it is just showing up blank again.

The title has been removed from the widget, you can now set your own title inside the widget settings.

Reviews are part of the widget. We're basically limited by what Goodreads lets us display. We've registered your suggestion and will keep it in mind for future features and updates of the Goodreads widget. Like making the widget more configurable.